Missoula Flood Tour

Join Whitman geology and environmental studies professor Bob Carson as we explore several stops while recreating the story of the Missoula Floods and how they shaped eastern Washington. Between 18,000 and 15,000 years ago, Clark Fork was repeatedly dammed by the Pend Oreille lobe of the Cordilleran ice sheet. Glacial Lake Missoula ruptured each ice dam, causing perhaps the greatest floods on Earth. First we’ll explore an overview of eastern Washington geology near the mouth of the Walla Walla River and Wallula Junction. Second, we’ll examine geological features such as Mazama ash and giant gravel bars along the mouth of Spring Creek. Last, we’ll take a short hike to the Two Sisters, a geologic feature along the Wallula Gap that overlooks the Columbia River.